In vehicles, there is an ever increasing need to convey fluids to different points that freeze even at relatively low temperatures, urea/water solutions freezing at −11° C., for example. It is therefore a known practice to heat the media lines required for this purpose. Since vehicles are becoming more and more compact in construction, the heatable fluid-carrying lines must also be fitted at points in the vehicle that are exposed to very high temperatures, e.g. 160° C. and above, during the operation of the vehicle. However, it is also important to ensure that the media line is heated as completely as possible, i.e. that both the media line and the connector are heated.
It is then the underlying object of the present invention to provide a preassembled media line which, on the one hand, allows virtually continuous heating and, on the other hand, ensures good thermal insulation against the effect of heat from outside, especially in the critical region of the connection between the media line and the connector.
According to the invention, the object set is achieved by virtue of the fact that the media line is provided with a heating wire and said heating wire is continued from the connector body and the media line, when connected, in such a manner that it is arranged at least partially on the coupling portion, and the connector body and the media line are enclosed at the end by a housing formed, in particular, from housing shells, the sealing function and a retaining function being divided between the housing and the connector body in the region of the coupling portion. In this arrangement, it is advantageous, in particular, if the coupling portion has the sealing means for sealing relative to the mating coupling part, and the housing has latching means for latching connection therewith. In this arrangement, it is advantageous, in particular, if the housing has the latching means for latching with the mating coupling part on its housing portion surrounding the coupling portion. By virtue of the division according to the invention of the sealing function and the retaining function between the connector body and the housing, the heating wire can be taken into the region of the latching means formed on the housing, thereby allowing extensive heating of the connector. The housing, which surrounds the connecting body, on the one hand, and the end of the media line, on the other hand, and is preferably composed of a thermally insulating material, ensures thermal protection for the point of connection between the media line and the line connector. Since the housing according to the invention is produced from housing half-shells, preferably two housing half-shells, the housing can be retrofitted around the connector body with the media line connected and after the heating wire has been passed through and fixed on the circumference of the coupling portion, the housing according to the invention simultaneously allowing a retaining function for the line connector and fixing of the media line. Moreover, it serves as thermal protection against external heat radiation. At the same time, the housing according to the invention also serves as a shield against the heat produced by the heating wire, thus preventing it from escaping to the outside. As regards its material properties, the connector piece according to the invention can be matched to the fluid to be conveyed in order to achieve the maximum possible thermal conductivity and resistance to chemical attack. For example, the connector body can be composed of stainless steel if the line is used to convey urea solutions. Furthermore, the two-piece construction of the line connector from an inner connector body and an outer housing makes it possible to dimension these two parts in such a way that there is an inner circumferential air gap between the two parts, thus allowing air gap insulation to be achieved. Separating the connector body and the housing likewise makes it possible to match the length of the housing in the region of the connecting portion of the media line to the particular requirements, thus enabling it to be extended as far as necessary over the media line to protect said line and to protect the connection point of the media line.
Uniform heat distribution over the entire coupling portion of the line connector can be achieved in the present invention if a heat-conducting element which conducts the heat from the heated region into the remaining region of the coupling portion is arranged on the coupling portion in a region which is not heated directly by the heating wire.